Flow Behavior of Isolate Protein from Soybeans var. Grobogan and Whey Protein Isolate at Acidic Condition under Various Heating Times

Warji Warji, Sutrisno Suro Mardjan, Sri Yuliani, Karin Schroën, Nanik Purwanti


Flow behavior of Soy Protein Isolate (SPI) suspension and Whey Protein Isolate (WPI) solution at pH 2.0 under various heating times were studied using steady shear viscosity measurements. Shear rate sweeps with increasing shear rates (up ramp) was performed to investigate the structural breakdown of the proteins during shearing. Down ramp shear rates were performed to check structural recovery of the proteins. The results showed that unheated SPI suspension has Newtonian flow; meanwhile, unheated WPI solution was slightly shear thickening. Heating the proteins at 80ºC for 4, 8, 12, and 16 h changed flow behavior of the proteins. Flow curve of SPI suspension heated for 12 h and 16, fitted Ostwald model with flow behavior index (n) of 0.625 and 0.264, respectively. This index indicates pseudoplastic (shear thinning) behavior, which also observed in heated WPI solution. The changes in flow behavior was attributed by the changes in protein structures, i.e., globular structures into fibrillar structures under prolonged heating at acidic condition. This conversion also increased the apparent viscosities of the proteins. SPI fibrils have higher apparent viscosities than WPI fibrils. This difference might be attributed to the detail fibril structures. SPI fibrils have branched and curvy structures; meanwhile, WPI fibrils are long and straight.

Perilaku aliran suspensi Soy Protein Isolate (SPI) dan larutan Whey Protein Isolate (WPI) pada pH 2.0 pada berbagai lama pemanasan diinvestigasi. Shear rate yang meningkat diaplikasikan untuk mengetahui kerusakan struktur protein selama geseran. Shear rate dengan pola menurun dilakukan untuk mengetahui apakah struktur
protein kembali ke struktur awal setelah mengalami kerusakan. Hasil penelitian menunjukkan bahwa suspensi SPI yang tidak dipanaskan memiliki perilaku aliran Newtonian; sementara larutan WPI yang tidak dipanaskan bersifat sedikit shear thickening. Pemanasan protein pada 80ºC selama 4, 8, 12, dan 16 jam mengubah perilaku aliran suspensi SPI dan larutan WPI. Kurva aliran suspense SPI yang dipanaskan selama 12 jam dan 16 jam sesuai dengan model Ostwald dengan indeks perilaku aliran (n) masing-masing 0.625 dan 0.264. Indeks ini mengindikasikan perilaku aliran bersifat pseudoplastic (shear thinning), yang juga teramati pada larutan WPI yang dipanaskan. Perubahan perilaku aliran disebabkan oleh perubahan struktur protein dimana SPI dan WPI awalnya memiliki struktur globular lalu menjadi struktur fibrillar akibat pemanasan yang lama pada kondisi asam. Perubahan struktur juga meningkatkan nilai apparent viskositas, dimana viskositas fibril SPI lebih tinggi daripada fibril WPI. Perbedaan ini diakibatkan oleh perbedaan struktur fibril protein dimana SPI berbentuk fibril yang bercabang dan melengkung sedangkan WPI berbentuk fibril yang lurus dan panjang.


flow behavior, protein fibrils, soy protein isolate viscosity, whey protein isolate.

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Akkermans, C., A.J. van der Goot, P. Venema, J.M. Gruppen and R.M. Boom. 2007. Micrometer-sized fibrillar protein aggregates from soy glycinin and soy protein isolate. Journal of Agricultural and Food Chemistry Vol. 55 (24): 9877-9882.

Barnes, H.A. 2000. A Handbook of Elementary Rheology. Cambrian Printers: Wales, UK.

Bazinet, L., M. Trigui and D. Ippersiel. 2004. Rheological behavior of WPI dispersion as a function of pH and protein concentration. Journal of Agricultural and Food Chemistry Vol. 52: 5366-5371.

Cramp, G.L., P. Kwanyeun and C.R. Daubert. 2008. Molecular interaction and Functionality of a coldgelling soy protein isolate. Journal of Food Science Vol. 73(1): E16-E24.

Dissanayake, M., L. Ramchandran and T. Vasiljevic. 2013. Influence of pH and protein concentration on rheological properties of whey protein dispersions. International Food Research Journal Vol. 20(5):


Dokic, L., T. Dapcevic, V. Krstonosic, P. Dokic and M. Hadnadev. 2010. Rheological characterization of corn starch isolated by alkali method. Food Hydrocolloids Vol 24: 172-177.

Donsì, G., G. Ferrari and P. Maresca. 2011. Rheological properties of high pressure milk cream. Procedia Food Science Vol. 1: 862 – 868.

Gomez-Mascaraque, L.G. and A. Lopez-Rubio. 2016. Protein-based emulsion electrospray micro-and submicroparticles for encapsulation

and stabilization of thermosensitive hydrophobic bioactive. Journal of Colloid and Interface Science Vol. 465: 259-270.

Hefnawy, H.T.M. and M.F. Ramadan. 2011. Physicochemical characteristics of soy protein isolate and fenugreek gum dispersed systems. Journal of Food Science and Technology Vol.48(3): 371-377.

Kamada, A., N. Mittal, L.D. Söderberg, T. Ingverud, W. Ohm, S.V. Roth, F. Lundell, and C. Lendel. Flow-assisted assembly of nanostructured protein

microfibers. Proceedings of the National Academy of Science of the United States of America, February 7, 2017. p 1232-1237.

Keerati-u-rai, M. and M. Corredig. 2009. Heat-induced changes in oil-in-water emulsion stabilized with soy protein isolate. Food Hydrocolloids Vol 23(2009):2141-2148.

Kuipers, B.J.H., G.A. van Koningsveld, A.C. Alting, F. Driehuis, H. Gruppen and A.G.J. Voragen. 2005. Enzymatic hydrolysis as a means of expanding the cold gelation conditions of soy proteins. Journal Agricultural Food Chemistry Vol. 53(4):1031-1038.

Lassé, M., D. Ulluwishewa, J. Healy, D. Thompson, A. Miller, N. Roy, K. Chitcholtan and J.A. Gerrard. 2016. Evaluation of protease resistance and toxicity of amyloid-like food fibrils from whey, soy, kidney bean, and egg white. Food Chemistry Vol 192(2016): 491–498.

Lee, H., G. Yildiz, L.C. dos Santos, S. Jiang, J.E. Andrade, N.J. Engeseth and H. Feng. 2016. Soy protein nano-aggregates with improved functional

properties prepared sequential pH treatment and ultrasonification. Food Hydrocolloids Vol. 55: 2000-2009.

Liang, Q., J. Zhang, C. Xu, J. Dou and S. Zhang. 2014. Influence of temperature, pH, and ionic strength on the rheological properties of oviductus ranae hydrogels. African Journal of Biotechnology Vol. 13: 2435-2444.

Liu, P., H. Xu, Y. Zhao and Y. Yang. 2017. Rheological properties of soy protein isolate for fiber and film. Food Hydrocolloids Vol. 64(2017): 149-156.

Liu, Q., R. Geng, J. Zhao, Q. Chen and B. Kong. 2015. Structure and gel textural property of soy protein isolate when subjected to extreme acid pH-shifting and mild heating process. Journal of Agricultural and Food Chemistry Vol. 63: 4853-4861.

Liu, Y., J. Yang, L. Lei, L. Wang, X. Wang, K.Y. Ma, X. Yang and Z.Y. Chen. 2017. 7S protein is more effective than total soybean protein isolate in

reducing plasma cholesterol. Journal of Functional Foods Vol. 36: 18-26.

Maceiras, R., E. Alvarez and M.A. Cancela. 2007. Rheological properties of fruit purees: Effect of cooking. Journal of Food Engineering Vol. 80(2007): 763-769.

Nurrahman. 2015. Evaluasi komposisi zat gizi dan senyawa antioksidan kedelai hitam dan kedelai kuning. Jurnal Aplikasi Teknologi Pangan Vol. 4(3):89-93.

Purwanti, N., Warji, S.M., Mardjan, S. Yuliani and K. Schroën. 2017. Preparation of Multi-layered Microcapsules from Nanofibrils of Soy Protein Isolate using Layer-by-Layer Adsorption Method.

Procedings of the 2nd International Conference on Agricultural Engineering for Sustainable Agriculture Production (AESAP 2017), Bogor, October 23-25, 2017.

Steffe, J.F. 1996. Rheological Methods in Food Process Engineering. 2ndEd. Freeman Press: East Lansing, USA.

Tang, C.H. and C.S. Wang. 2010. Formation and characterization of amyloid-like fibrils from soy b-conglycinin and glycinin. Journal of Agricultural and Food Chemistry Vol. 58(20): 11058–11066.

Tang, C.H., S.S. Wang and Q. Huang. 2012. Improvement of heat-induced fbril assembly of soy β-conglycinin (7S Globulins) at pH 2.0

through electrostatic screening. Food Research International Vol. 46(2012): 229-236.

Warji, S.S. Mardjan, S. Yuliani and N. Purwanti. 2017. Characterization of nanofibrils from soy protein and their potential applications for food thickener and building blocks of microcapsules. International Journal of Food Properties Vol. 20(sup1):S1121-S1131.

Wongkanya, R., P. Chuysinuan, C. Pengsuk and P. Nooeaid. 2017. Electrospinning of alginate/ soy protein isolated nanofibers and their release characteristics for biomedical applications. Journal of Science: Advanced Materials and Devices Vol.2(3): 309-316.

Xiao, J., C. Shi, L. Zhang, Y. Li, J. Qi, Y. Wang and Q. Huang. 2016. Multilevel structural responses of β-conglycinin and glycinin under acidic or alkaline heat treatment. Food Research International Vol.89(1): 540-548.

Xia, W., H. Zhang, J. Chen, H. Hua, F. Rasulov, D. Bi, X. Huang and S. Pan. 2017. Formation of amyloid fibrils from soy protein hydrolysate: Effects

of selective proteolysis on β-conglycinin. Food Research International Vol. 100: 268-276.

Yildiz, G., J. Andrade, N.E. Engeseth and H. Feng. 2017. Functionalizing soy protein nano-aggregates with pH-shifting and mano-thermo-sonication. Journal of Colloid and Interface Science Vol. 505(2017): 836–846

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